Machine-switching telephone system



H. P. CLAUSEN. MACHINE SWITCHING TELEPHONE SYSTEM. APPLICATION FILE!)05c. 26. m1.

HENRY P. CLAUSEN, 0F MOUNT "VIEIRNON, NEW YORK, ASSIGNOR TO WESTERNELEC- TRIO COMPANY, INCORPORATED, 035 NEW YORK, N. Y., A CORPORATION OFNEW roan.

Specification or Letters Patent.

1lEAGI-IINESWITCHING TELEPHONE SYSTEM.

Patented @ct. 111, 1%21.

Application filed December 26, 191?- Serial No. 208,844.

eflect certain operating refinements and improvements whereby anestablished connection may be more closely supervised by the parties tothe connection.

More iarticularly the object is to provide means controllable by eitherthe called or calling party to signal the other when the other, eitherthrough a misunderstanding or otherwise, has prematurely replaced hisreceiver on its hook.

A feature of this invention is a means to bring about the desiredresult. This means is arranged to be responsive to the rapid movementsof a subscribers switchhook so that the operation 01": recalling theother subscriber in this system simulates the operation of attractingthe operators attention in any well-known manual system. Or this meansmay equally well respond to a manipulation of a subscribers callingdevice.

According to another feature, this means is rendered ineliective whenboth parties have their receivers off their respective hooks so that oneparty may not maliciously or otherwise cause ringing current to beapplied to the others line. I

According to a further-feature, ringing current is instantly pplied tothe called part-ys line as soon as the automatic apparatus connected to,tested and found idle as such called line.

The drawings disclose in Figure 1 so much of a complete circuit involvedin an established. connection between two substations as is necessary toa clear understimding of the invention.

In Fig. 2, the modification of a slow acting arrangement employed inFig. 1, is diagrammatically shown.

The subscriber at substation 1 may in any ordinary manner establishconnection to the connector switch which "forms the main part of Fig. 1.The brushes 2, 3 and i ot' a selector switch are then placed on theterminals 5, 6 and 7 of the trunk terminating in its connecting switch.Thereupon a circuit is established from ground, battery, the right-handwinding of line relay 8, the normal contact of armature 9 of relay 10,lower talking conductor leading to the subscribers line through thelower normal contact of relay 11, terminal 6, brush 8, to and throughthe subscribers apparatus at substation 1, brush 2, terminal 5, uppernormal contact of relay 11, upper talking conductor, normal contact ofarmature 12 of relay 10, the lefthand winding of relay 8 to ground.Through this circuit relay 8 is energized, and being of the type knownas a quick relay, will respond to the manipulation of the subscriberscalling device. At each opening of the circuit just traced, relay 8 willactuate its armatures.

Upon the first energization of relay 8, a circuit is established fromground, the righthand armature and alternate contact of relay 8, windingof relay 13 to battery and ground. 7

Relay 13 attracts its armatures and by placing ground on the terminal 7,through left-hand armature and alternate contact, marks the seized trunkas busy.

When the subscriber at substation 1 manipulates his dial, each break ofthe line circuit of relay 8 establishes a circuit from ground,right-hand armature and normal ture 14.- of relay 15, winding of relay16,

winding of primary magnet 17, first position contact and side-switch arm18 to battery and ground. Through this circuit, re-

lay 16 andmagnet 17 are energized. Magnet 17 responds to each separatebreak in the subscribers line and relay 16 holds over untilthe series ofimpulses has ceased.

The energization of magnet 17 drives brushes 19, 20 and 21 in a primarydirection in any well-known manner. Relay 16 in attracting its armaturesenergizes the escapeme'nt magnet 22, through its right-hand armature andalternate contact. At the end of the series oi? impulses, which serve tomove the brushes 19, 20 and 21 in the primary direction a requisitenumber of steps, relay 16 after a short interval becomes deenergized andin turn the escapement magnet 22 becomes deenergized. In response tothis deenergization the side-switch wipers are moved into their secondpositions.

Thereupon the calling subscriber may now send the last series ofimpulses which will "cause current to flow through a circuit fromground, right-hand armature and normal Should this line prove to bebusy, ground will be found on the terminal 25, leading from ground,third position contact and sideswitch wiper 26 of another connectorswitch,

- to battery and ground.

brush 21 of this other connector switch, a multiple of terminal 25,thence to brush 21, side-switch wiper 26 and its second positioncontact, normal contact 01 armature 27 of relay 23, right-hand windingof relay 23, normal contact of the right-hand armature of relay 16 (whenrelay 16 becomes deenergized after the second series of impulses),winding of escapement magnet 22 Through this circuit the escapcmentmagnet 22 is held in an energizing position and the side-switch wipersare not allowed to move into their third positions. Also a source ofbusy tone current is connected to the calling subscribers line fromtransformer 28, contact and inner right-hand armature of relay 23, lowerlimb of the talking conductors, le1tt-hand winding of relay 10 tobattery and ground, whereby through the inductive action of the twowindings, this tone is transmitted to the calling subscribers line inthe well-known manner.

If on the other hand the called subscribers line is idle, terminal 25will be found to be ungrounded and the escapement magnet 22 will not beheld up in the manner described. Therefore, upon its deenergization, thesideswitch wipers will be moved into their third positions and relay 15will be energized through a circuitleading romground, third positioncontact and side-switch wiper 26, relay 15, third position contact andsideswitch wiper 18to battery and ground. It should be noted here thatthe cscapement magnet 22' is arranged to move the side switch wipersinto their third position im mediately after the relay 16-becomesdeenergized. During the energization of relay 16, a circuit isestablished from ground, lefthandarmature and contact of relay 16, relay29 to battery and ground, which relay being slow to release will holdits armatures in their attracted positions for a short interval aftertheside-switch wipers have been moved into their third positionand there lay 15 has been energized as described. Therefore immediately thatthe called subscribers line is seized, a ringing current is transmittedfrom a source of ringing current 30, the alternate contact and lowerarmature of relay 29, the innermost lower armature and contact of relay15, brush 20, terminal 30 to and through the bell circuit of the calledsubscribers line, terminal 31, brush 19, the contact and upper armatureof relay 15, the upper armature and alternate contact of relay 29 toground. The energizing circuit for relay 29, however, is not maintained,so that after a short interval it retracts its armature, whereupon asource of intermittent ringing current is connected to the calledsubscribers line. This source of intermittent ringing current is hereshown as a ringing current generator connected to the alternate contactand ground connected to the normal contact oi? relay 33 intermittentlyenergized through a circuit in which is included an interrupter 34-.This source of intermittent ringing current is then connected to theinnermost lower armature of a relay thence through the normal contactand lower armature of relay 29 over the circuit previously described, tothe upper armature and normal contact of relay 29, the upper armatureand normal contact of relay 35, the upper winding of relay 35 to batteryand ground.

Through this circuit the ringing of the called subscribers bell isintermittently con tinued. When the called subscriber, in answering thesummons of his bell, removes his receiver from its hook, the flow 0t current ust described is so increased that the relay 35 will attract itsarmatures, thereby cutting off this flow of current and substitutingtherefor a flow oi? talking current from the windings of relay 10. Theattraction of its armatures by relay 35 establishes a locking circuitfrom ground, battery, lower winding of relay 85, alternate contact andlowermost armature of relay 35, primary oilnormal contact 36 to ground.

Talking current is now supplied from ground primary oil-normal contact36, through the lowermost armature and contact of relay 35, theright-hand winding of relay 10, the alternate contact and upper armatureof relay 35, thence over the circuit previously described to theinnermost lower armature of relay 35 and its alternate contact.left-hand winding of relay 10 to battery and ground. Relay 10 inattracting its armature interposes a break in the circuit of the releasemagnet 37 and at the same time reverses the flow of current in thecalling subscribers line in the well-known manner.

The release of this switch depends upon the combined action of thecalling and called subscribers. lVhen both have hung up their receiversand relays 8 and 10 have both tion and should the called subscriber wishto recall him, it may be done through the rapid manipulation of theswitchhook at the called subscribers station li-4:. The rapidmanipulation of the switchhook at this point will cause the armatures ofrelay 10 to vibrate. As long as relay 10 is in an energizing position, acircuit will be established from ground, contact and armature 45 ofrelay l0, winding of relay 38 to battery and ground. Through its innerleft-hand armature relay-38 completes a circuit through the winding ofrelay 39 which in turn attracts its armatures. Upon the first break inthe called subscribers line relay 10 momentarily retracts its armature,thereby opening the energizing circuit of relay lt retracts itsarmatures and thereby a circuit is established from ground, through theinnermost left-hand armature and normal contact of relay 38, theleft-hand armature of relay 39 (which being slow to release holds itsarmature attracted), and thence through the winding of relay 40 tobattery and ground. Following this action relay 10 attracts its armatureand a circuit for the energization of relay 38 is reestablished.Thereupon relay 41 is energized through a circuit extending from ground,outermost armature of relay 38, armature and contact of relay 40 to thewinding of relay 41 to battery and ground. Upon the second break in thecalled subscribcrs line, the relay 38 is deenergized momentarily.whereby a circuit is established from ground, the outer lefthandarmature and normal contact of relay 38 through the armature and contactand 1-2 energized and in turn the relay 11 will remain energized.

This will cause ringing current from the generator 46 to flow throughthe alternate contact and lower armature of relay 11, terminal 6, brush3, to and through the bell circuit at the substation 1, brush 2,terminal 5, upper armature and alternate contact of relay 11 to ground.

It will be noticed that, in a similar manner, the subscriber atsubstation 1 may cause the relay 29 to become energized should thecalled subscriber prematurely hang up his receiver. If, in answer to thefirst summons sent, the subscriber does not answer, the callingsubscriber may cause the relay 29 to again become energized by actuatinghis switchhook.

It should also be noticed that, after a connection is established,should either subscriber attempt to cause the flow of ringing current inthe other subscribers instrument, he will fail, for as long as thesubscriber toward whom this action is directed has his receiver oil thehook, the circuit of the ringing relay associated with his end of theline will be disconnected at the outermost left-hand armature ol hissupervisory relay.

Fig. 2 represents a modification of the slow acting mechanismrepresented by the train of relays 38 to l2 inclusive. Relay 1()corresponds to relay 10 of Fig.1 and relay 8 corresponds to relay 8 ofFig. 1. There is this difference in the construction, however, that theinnermost armature and contacts are arranged so that ground istransmitted to the winding of a slow acting magnet 38 only during themovement of said armatures. Being of the make-before-break type, thisground is connected only while the armature is in transit. Thus themanipulation of a subscribers switchhook will cause a series of impulsesfrom ground, the contacts of either supervisory relay, the winding ofslow acting magnet 38 to battery and ground. Upon the first impulse,this magnet so moves its plunger 50 that the contact 51, whichcorresponds to the righthand armature and contact of relay 39, isopened. It a train of several impulses is sent to the winding of magnet38 in the manner described, the roller 52 associated with the plunger 50will come in contact with the lever 53 and moving upwardly will displacethe lever 53 toward the right. Upon the outer movement of the plunger 50in re sponse to the cessation of impulses, the roller 52 coming incontact with the upper side of the bent portion of lever 53 will causeit to be displaced to the left, whereupon a circuit is established fromground, the contact 54:, the lever 53, and thence to the outermostleft-hand armature of that supervisory relay controlled by thesubscriber who has prematurely hung up, and in the manner previouslydescribed either the relay 11 or 29 will be energized and the subscriberrecalled.

- WVhat is claimed is 1. In a telephone system, telephone lines, a callbell associated with each of said lines, selective switches controlledby a calling subscriber for establishing connections between said lines,and means under control of either of two lines involved in a connectionfor operating the call bell of the other.

2. In a telephone system, telephone lines, acall bell associated witheach of said lines, selective switches for establishing connectionsbetween said lines, meansfor operating the call bell of a called line,and means under control of either a calling or called line for operatingthe call bell of a calling or called line.

3. In a telephone system, telephone lines, selective switches controlledby a calling subscriber for establishing connections between said lines,means for instantaneously signaling the called line upon theestablishment of a connection, means for resignaling the called linebefore disestablishing the connection, and means for signaling thecalling I line before the disestablishment of the connection,

. connection, means under control of said calling line for subsequentlyoperating the call bell of said called line, and means under control, ofsaid called line for operating the call bell of said calling line.

5. In a telephonesystem, a calling line, a called line, subscribercontrolled means for establishing a connection therebetween, meansforsignaling said called line upon the establishment of such connection,means, under control of said calling line for resignaling said calledline, means under control of said called line for signaling said callingline, and means under control of the signaled line for disabling saidsignaling means.

6. In a telephone system, a calling line, a called line, electricallyoperated switching devicesfor establishing a connection therebetween,means for instantaneously signaling said called line upon theestablishment of such connection, means under control of 7 said callinglinefor resignaling said called line, and means under control of saidcalled line for signaling said calling line.

7. In a telephone system, the combination of telephone lines, a callbell associated with each of said lines, switching means for interconnecting said lines and a source of signaling current for actuatingsaid call bells,

- of a slow releasing relay included in said switching means forcontrolling the application of said signaling current to said lines,

a circuit for the transient energization of said relay incident to theestablishment of a connection, means under control of a calling line forthereafter reestablishing said circuit.

8. In a telephone system, the combination of telephone lines, a callbell associated with each of said lines, switching means forinterconnecting said lines and a source of signaling current foractuating said call bells, of a slow releasing relay included in saidswitching means for controlling the application of said signalingcurrent to said lines, a circuit for the transient energization of saidrelay incident to the establishment of a connection, means under controlof a calling line for thereafter reiistablishing said Cir cuit, andmeans unoer control of the signaled line for opening said circuit.

, 9. In a telephone system, a combination of telephone lines, a callbell associated with each of said lines, a connector switch in whichsaid lines terminate, means for setting said connector switch on saidlines, and a source of signaling current for actuating said call bells,of a relay for controlling the application of said signaling current tothe line upon which said switch has been set, of a second relay forcontrolling the application of said signaling current to the line underthe control of which said switch has been set, means under control ofsaid calling line for energizing said first relay, and means undercontrol of the called line for energizing the said second relay.

10. In a telephone system, a calling line, a called line, means forintercoimecting said lines, means under control of either of said lineswhen interconnected for signaling the other, said signaling meansincluding a slow acting mechanism responsive to a series of impulsescreated in either of said lines.

11. In a telephone exchange system, a calling line, a called line, meansfor interconnecting said lines including means for signaling said calledline incident to the establishment of a connection between said lines,and a slow acting mechanism responsive to a series of impulses createdin either of said lines for signaling the other.

12. In a telephone exchange system, a ealling line, a called line, meansfor interconnecting said lines including means for signaling said calledline incident to the establishment of a. connection between said lines,a slow acting mechanism responsive to a series of impulses created ineither of said lines for signaling the other, and means for nullifyingthe effect of said mechanism.

In witness whereof, I hereunto subscribe my 7name this 18th day ofDecember, A. D. 191

HENRY P. CLAUSEN.

